Words: Tommy Parry
“Project Havoc,” as it was affectionately titled, started its life as a farm truck for James, who was aged just 15 when his parents picked it up. He started a long love affair with this GMC then and there; he rebuilt the 355, redid the interior and eventually tore it down to the bare frame. Here begins a long love-hate story between a man and his truck.
Well, after a few blown motors and a coat of fresh aquamarine paint, James set out to make sure he did this beaut justice. First came a motor that would last. He opted for a 358 with an Eagle bottom, a Crane XE274 cam, a set of World Products Sportsman heads, Speedpro Hyper pistons, Scorpion rocker rollers, an Edelbrock water pump and intake, a Mallory distributor, a Holley Street Avenger carburetor and ARP heads throughout.
Then came the time for a complete teardown; pulling the aquamarine interior, stripping the buckets and, after seeing the clean interior, finding some encouragement for the lengthy chassis work ahead.
After removing the crossmembers from the frame, James realized the sorry state it was really in. He cleaned it all up with a grinder, then set some braces in anticipation for boxing the frame. After attaching a 7” brake booster with a Corvette’s cylinder, it looked like a had a foundation ready for a little more grunt. Fortunately, he had plenty where that came from, but mounting the motor was no picnic.
To keep the headers from contacting the mounts, he moved the motor back 3 inches. He then added some DOM tubing and installed it in the boxed rails for the powersteering box, since he needed a little extra strength for the quicker ratio.
After installing his differential, watts link and rear anti-roll bar, he could step back briefly. After 134 hours invested into this build, his Chevy’s rear end was resembling something closer to the Pro Touring-end of the hot rod spectrum. Why not see if a classic truck can corner like a modern sports car?
However, James was not interested in a soulless sports machine. He had his eye on a set of chrome five-spokes, and after painting the frame midnight black, doused the 389 in some metallic green paint. It might be visible to only a few, but those who have the privilege of seeing the GMC’s innards will stare slack-jawed.
Well, he wanted even more pizazz from this package. He chopped the bed by eight inches in the back and a foot towards the front. Seeing as it was immaculate before he put it under the knife, it wasn’t the easiest part of this build. Yet the final product gave it shorter overhangs, and if James wanted this truck to corner, bringing that mass inwards somewhat would only help.
A teardown of the interior included new Auto Meter gauges, a wood-rimmed wheel, an Alpine deck and amps and tan benches. It may’ve rolled and looked lovely, but James still had a few loose ends he needed to tie up. First, he replaced the ignition with an MSD Pro Billet setup, which allowed him to run much smoother — and he somehow manages 25 miles to the gallon. On went some Magnaflow mufflers and tips, and the whining 4L60e was replaced with a fresher version. To complement a stout gearbox and plenty of grunt, James stuck on a set of Moser rear axles to minimize any chances of snapping.
After a few hiccups, the motor turned over, and James went on his celebratory maiden cruise. The thing had giddy and was willing to roast the rears with the slightest tap of the loud pedal. However, cheap timing covers meant one pull led to a small bang and a cloud of black smoke. No cause for alarm — he dawdled home, put a quart of oil in the motor and replaced the timing cover the next day. What was important, though, was that this thing could flat-out haul!